Results obtained from the Solver tool in Microsoft Excel were used to create the maps below. The estimated weighted costs of transporting waste from all over the island to the two regions are also stated with the units tonnes-km/day.
The weighted distance cost obtained for the scenario to build the incineration plant at Tuas (Region 1) is 183,612 tonnes-km/day.
As for Senoko (Region 2), the weighted distance cost obtained is 162,361 tonnes-km/day.
With the two weighted distance cost values, it is observed that it would be more economical to site the 5th incineration plant in Senoko (Region 2) than at Tuas (Region 1) as the weighted cost of transporting waste islandwide to the incineration plants is much less in the former scenario. This difference is 183,612 – 162,361 = 21,251 tonnes-km/day. Assuming that each truck carries around 5 tonnes of waste every trip, the potential distance less travelled would be 21,251 / 5 = 4,250 km/day. Given that Singapore spans only roughly 49 km from east to west and 24 km from north to south, the potential trips avoided every day is very substantial. This will not only help save costs within the waste management industry in Singapore, but also bring about attendant benefits such as alleviating road congestion since the trucks need to ply the roads less often.
part 2: cost distance analysis
results
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Click image to enlarge
(PDF, 1.7mb)
(PDF, 1.7mb)